3‐Phenyl‐4‐acyl‐5‐isoxazolones as Reagents for the Solvent Extraction Separation of Titanium(IV) and Iron(III) from Multivalent Metal Chloride Solutions

Abstract

This paper embodies the results of the investigations carried out on the extraction of magnesium(II), aluminum(III), titanium(IV), vanadium(V), chromium(III), manganese(II), and iron(III) from hydrochloric acid solutions (0.01–2.0 mol dm−3) using various 3‐phenyl‐4‐acyl‐5‐isoxazolones, namely, 3‐phenyl‐4‐(4‐fluorobenzoyl)‐5‐isoxazolone (HFBPI), 3‐phenyl‐4‐benzoyl‐5‐isoxazolone (HPBI), and 3‐phenyl‐4‐(4‐toluoyl)‐5‐isoxazolone (HTPI). The results demonstrate that titanium(IV) and iron(III) are extracted in xylene as: where HX refers to the 3‐phenyl‐4‐acyl‐5‐isoxazolones and K ex,Ti(IV) and K ex,Fe(III) denotes the equilibrium constants for titanium(IV) and iron(III), respectively. On the other hand, magnesium(II), aluminum(III), vanadium(V), chromium(III), and manganese(II) are not found to be extracted in the organic phase. The equilibrium constants of the extracted complexes have been calculated by non‐linear regression analysis by taking into account the aqueous phase complexation of metal ion with inorganic ligands and all plausible complexes extracted in the organic phase and are found to be K ex,Ti(IV) = 2.80 ± 0.03, 2.54 ± 0.04, 2.41 ± 0.04 and K ex,Fe(III) = 4.35 ± 0.03, 4.12 ± 0.04, 4.07 ± 0.04 for HFBPI, HPBI, and HTPI, respectively. The IR spectral studies of the extracted complexes were used to further clarify the nature of the extracted complex. The separation and recovery possibilities of titanium(IV) and iron(III) from other associated metal ions, viz., magnesium(II), aluminum(III), vanadium(V), chromium(III), and manganese(II), which are present in the titanium minerals processing industry have also been discussed.